QUERY PLAN
GroupAggregate (cost=158.85..158.99 rows=6 width=12)
Group Key: parent_id
-> Sort (cost=158.85..158.88 rows=10 width=4)
Sort Key: parent_id
-> Seq Scan on tbl_tasks (cost=0.00..158.69 rows=10 width=4)
Filter: (parent_id = ANY ('{1545,1535,1537,1547,1546,1548,1543,1536,1549,1544}'::integer[]))